Dual-cylinder compaction apparatus



United States Patent [72] Inventor Milton Clar Bethesda, Maryland [211 App]. No. 747,676 [22] Filed July 25, 1968 [45] Patented Nov. 24, 1970 [73] Assignee Auto Pak Company Bladensburg, Maryland a corporation of the District of Columbia [54] DUAL-CYLINDER COMPACTION APPARATUS 2 Claims, 4 Drawing Figs.

[52] US. Cl 100/229, 92/111, 100/269 [51] Int. Cl B301) l/32 [50] Field of Search 92/111;

[56] References Cited UNITED STATES PATENTS 71,329 11/1867 Robinson et al... 92/111 2,688,313 9/1954 Bauer 92/1 1 IX 2,847,188 8/1958 Wiltse. 92/111X 3,368,478 2/1968 Clar 100/50 Primary ExaminerBil1y J. Wilhite AttorneyShapiro and Shapiro ABSTRACT: Hydraulically-driven compaction apparatus for refuse and the like in which the drive ram comprises a pair of cylinders fixed side-by-side and having oppositely extending piston rods, one of which is fixed to the compaction blade and the other of which is fixed to the frame. The latter piston rod has a pair of internal passages which permit hydraulic fluid to be supplied to and returned from the cylinders by connections to ports at the fixed end of the rod, corresponding ends of the cylinders being interconnected hydraulicallyv Sheet i tznte d Nov. 24, 1970 I INVENTOR M l LTO N C LAR BY Sficyaz'ro and Sfigpz'm ATTORNEYS 1 DUAL-CYLINDER COMPACTION APPARATUS BACKGROUND OF THE INVENTION This invention relates to compaction apparatus for refuse and the like and is more particularly concerned with an improvement in the compaction apparatus disclosed and claimed in the applicants prior US. Pat. No. 13, I968, for Compaction Apparatus".

The foregoing patent discloses compaction apparatus in which the compaction blade is driven by a ram including a pair of hydraulic cylinders fixed to each other side-by-side and having oppositely extending piston rods. one of which is fixed to the compaction blade and the other of which is fixed to a frame member, so that the cylinders are supported by the piston rods and move relative to the frame. This apparatus provides excellent compaction while minimizing the overall length of the apparatus by virtue of theram configuration and its relationship to the compaction blade and frame. Hydraulic connections to the cylinders are provided by hydraulic lines which pass from the cylinders through an opening in the boxlike blade structure to the stationary portion of the hydraulic system. Although flexing of these lines can be reduced by proper routing, line damage due to flexing can nevertheless be troublesome.

BRIEF DESCRIPTION OF THE INVENTION the other of which is connected to a frame member, and in which the supply and return hydraulic connections to the cylinders are made at the end of the piston rod fixed to the frame member, the rod having a pair of longitudinal passages for the supply and return of hydraulic fluidto and from opposite sides of the pistons, corresponding ends of the cylinders being hydraulically interconnected.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects, advantages, and features of the invention, and the manner in which the same are accomplished will become more readily apparent upon consideration of the following detailed description of the invention taken in conjunction with the accompanying drawings, which illustrate a preferred and exemplary embodiment, and wherein:

FIG. I is a contracted longitudinal sectional view of a cylinder constructed in accordance with the invention;

FIG. 2 is an end view of the cylinder of FIG. 1;

FIG. 3 is a schematic hydraulic diagram illustrating the problem solved by the invention; and

FIG. 4 is a side elevation view illustrating typical compaction apparatus incorporating the invention.

DETAILED DESCRIPTION OF THE INVENTION Reference is made to the aforesaid Letters Patent for a detailed description of the type of compaction apparatus in which the present invention may be incorporated. For the present description it suffices to state, with reference to FIG. 4, that the compaction apparatus preferably comprises a packer including a frame having a rectangular compaction chamber 12 adjacent to one end thereof, the chamber having an inlet opening at the top for communication with a hopper 14 into which refuse or other material to be compacted is placed and having an outlet opening at the front 16 and being open at the rear 18 for the passage of a boxlike compaction 3,368,478, granted Feb.

blade 20. The blade has a top wall 22 which blocks the inlet opening to the compaction chamber when the blade is extended but which permits material to enter the compaction chamber when the blade is retracted. A suitable container 24 (shown in phantom lines) is detachably connected to the packer and has an opening at one end thereof which mates with the outlet opening at the front 16 of the packer, so that material may be forced by the blade 20 through the compaction chamber 12 and compacted into the container 24. In addition to the vertical frontwall 26, which constitutes the packing surface of the blade, and the horizontal top wall 22, the blade compriscsa short bottom 28 and a pair of L-shaped side walls 30 which are elongated along the top wall 22 and have guides 32 for supporting the blade upon corresponding longitudinal tracks 34 of the frame I0, the bottom wall 28 of the blade also being supported by suitable guides upon the bottom wall of the compaction chamber. The frame also supports a vertically adjustably deck 36 onto which refuse receptacles may be rolled for dumping into the hopper [4.

The blade is driven by a dual-cylinder hydraulic ram 38. including a pair of cylinders 40 and 42 fixed to each other, one above the other, in sideby-sidc relation and containing pistons the rods 44 and 46 of which extend in opposite directions. The exposed end of rod 44 is fixed to a transverse frame member 48, and the exposed end of rod 46 is fixed to the back of the front wall 26 of the blade, cylinders 40 and 42 being suspended from the associated piston rods.

FIG. 3 illustrates the hydraulic system, which in addition to the cylinders 40 and 42, includes a pump 50 driven by an electric motor 52, two-position control valve 54 moved to one position by solenoid 56 and to the other position by a spring (not shown), fluid reservoir 58, check valve 60, and hydraulic lines 62 and 64. With the control valve 54 in the position shown, fluid is supplied by pump 50 through check valve 60 and the hydraulic line 64 to the rear end of cylinder 40, which is interconnected to the corresponding front end of cylinder 42, fluid being returned from the rear end of cylinder 42 and the corresponding front end of cylinder 40 through line 62 to the reservoir 58 from which the pump draws hydraulic fluid. Since the exposed end of piston rod 44 is fixed to the frame member 48, the piston rod cannot move relative to the frame, and the admission of hydraulic fluid to the front end of cylinder 42 will cause the cylinder to move to the left in FIG. 3 (and to the right in FIG. 4) carrying cylinder 40 with it. Admission of fluid to the rear end of cylinder 40 will cause the piston rod 46 to extend from the cylinder, the result of which is thatboth cylinders will move away from the frame member 48, and the blade 20 will move away from the cylinders as well as from the frame member 48. When the control valve 54 is in its other position, the blade and the cylinders will move in the opposite direction toward the frame member 48. Although the portions of the hydraulic lines 62 and 64 which interconnect the corresponding ends of the cylinders do not flex, the portions (shown in phantom lines) which extend from the ram to the control valve 54 are subject to constant flexing as the blade moves back and forth if hydraulic connections are made directly to the cylinders. In accordance with the invention this problem is overcome by constructing cylinder 42 as will now be set forth with reference to FIGS. 1 and 2.

Cylinder 42 has ports 66 and 68 through the side wall thereof adjacent to the end 70 of the cylinder from which the piston rod 44 projects and adjacent to the closed opposite end 72, respectively. Ports 66 and 68 are interconnected with ports adjacent to the corresponding ends of cylinder 40, which is not shown in FIGS. 1 and 2. Brackets 74 and 76 welded to cylinder 42 permit the cylinder to be fixed in side-by-side relationship to cylinder 40, which is provided with mating brackets secured to brackets 74 and 76 as by bolts.

Piston rod 44 is hollow, comprising a pair of coaxial sleeves 78 and 80 which define a pair of longitudinal fluid passages 82 and 84. The sleeves are fixed to each other at the opposite ends of the rod. The exposed end of rod 44 has a pair of ports 86 and 88 which communicate with passages 82 and 84,

respectively, and which extend transversely through the rod end for connection to the supply and return lines. It will be noted that hydraulic fluid may pass to or from port 86 and along the length of passage 82 to a port 90 at the opposite end of passage 82, by which fluid may enter or leave the annular space 91 between end 72 of the cylinder and the piston 92 fixed upon the rod 44 within the cylinder. Fluid may also pass through port 88 and passage 84 and through port 94 at the opposite end of passage 84 to or from the annular space 96 between piston 92 and end 70 of the cylinder. It will be noted that fluid passing te m from spaces 91 and 96 also passes through ports 68 and 66, respectively, so that the cylinders are supplied in parallel. Although only the upper half of the internal constructionofcylinder 42 is shown in FR]. 1. it will be apparent that the hidden lower half is substantially identical, except that the lower half need not be provided with a separate port 94. Piston 92 may be secured upon the mating stepped end of the piston rod by a nut 98 threaded onto the rod end. appropriate piston rings 100 and an O-ring 102 being provided as shown. The wall at end 70 ofthe cylinder may comprise two parts, the outer being threaded into the mating end of the cylindrical side wall and provided with a set screw 102'. rings 104 and 106, and seals or packings 108 and 110 also being provided.

By virtue of the invention, the hydraulic lines coupled to ports 86 and 88 are no longer subject to flexing, since the exposed end of piston rod 44 is fixed to the frame. The hydraulic fluid passes through the longitudinal passages in rod 44 for movement to and from spaces 91 and 96 on opposite sides of piston 92 and via ports 66 and 68 to and from the corresponding spaces of cylinder 40. It is thus possible to provide compaction apparatus with a dual-cylinder hydraulic ram drive and have all of the advantages of the dual-cylinder construction as well as the advantages of conventional drives employing fixed cylinders.

While a preferred embodiment of the invention has been shown and described, it will be apparent to those skilled in the art that changes can be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims.

lclaim:

l. Compaction apparatus and the like comprising a frame having a compaction chamber adjacent to one end thereof provided with a compaction blade movable in the chamber and a hydraulic rain including a pair of hydraulic cylinders fixed to each other side-by-side and containing pistons with piston rods extending from said cylinders, respectively, in opposite directions, one of said rods having its exposed end connected to said blade and the other of said rods having its exposed end connected to said frame adjacent to the other end thereof. corresponding ends of said cylinders being hydraulically interconnected by passage means fixed at opposite ends to said cylinders. respectively. the piston rod connected to said frame having a pair of longitudinal passages therethrough. one of which has a first port adjacent to the exposed end of its rod and a second port adjacent to the opposite end of its rod communicating with the cylinder space at one side of the associated piston, and the other of which has a first port adjacent to the said exposed end of its rod and a second port communicating with the cylinder space at the opposite side of the associated piston, whereby hydraulic fluid may be supplied to and returned from both the said cylinders by connections to the first said ports.

2. The apparatus of claim 1, wherein said rod provided with the longitudinal passages comprises a pair of coaxial sleeves fixed to each other adjacent to the respective opposite ends thereof. 

